H⁺‐pyrophosphatase from Salicornia europaea confers tolerance to simultaneously occurring salt stress and nitrogen deficiency in Arabidopsis and wheat

Abstract

High salinity and nitrogen (N) deficiency in soil are two key factors limiting crop productivity, and they usually occur simultaneously. Here we firstly found that H(+) -PPase is involved in salt-stimulated NO3 (-) uptake in the euhalophyte Salicornia europaea. Then, two genes (named SeVP1 and SeVP2) encoding H(+) -PPase from S. europaea were characterized. The expression of SeVP1 and SeVP2 was induced by salt stress and N starvation. Both SeVP1 or SeVP2 transgenic Arabidopsis and wheat plants outperformed the wild types (WTs) when high salt and low N occur simultaneously. The transgenic Arabidopsis plants maintained higher K(+) /Na(+) ratio in leaves and exhibited increased NO3 (-) uptake, inorganic pyrophosphate-dependent vacuolar nitrate efflux and assimilation capacity under this double stresses. Furthermore, they had more soluble sugars in shoots and roots and less starch accumulation in shoots than WT. These performances can be explained by the up-regulated expression of ion, nitrate and sugar transporter genes in transgenic plants. Taken together, our results suggest that up-regulation of H(+) -PPase favours the transport of photosynthates to root, which could promote root growth and integrate N and carbon metabolism in plant. This work provides potential strategies for improving crop yields challenged by increasing soil salinization and shrinking farmland.

H+‐pyrophosphatase IbVP1 promotes efficient iron use in sweet potato [Ipomoea batatas (L.) Lam.]

“…Increased biomass, especially root system, has been reported in plants overexpressing type I H + ‐PPases, under deficiencies of phosphate (Gaxiola et al ., 2012; Pei et al ., 2012; Yang et al ., 2007, 2014) and nitrogen (Lv et al ., 2015; Paez‐Valencia et al ., 2013). The type I H + ‐PPase AVP1 triggers auxin efflux by up‐regulating the expression of Pinformed 1 auxin efflux facilitator and P‐adenosine triphosphatase, in Arabidopsis (Li et al ., 2005) and AUX1 , PIN1a and PIN1b in maize (Pei et al ., 2012).…”

“…It increases root and shoot biomass, photosynthetic capacity and nutrient uptake under normal or nutrient‐limited conditions, such as low NO 3− and Pi (Khadilkar et al ., 2016; Li et al ., 2005; Lv et al ., 2015; Paez‐Valencia et al ., 2013; Pizzio et al ., 2015; Yang et al ., 2007, 2014). Rhizosphere acidification is a principal mechanism in plant mineral nutrition, because it contributes to nutrient solubility and proton‐motive force in the plasma membrane (Palmgren, 2001).…”

Non-uniform salinity in the root zone alleviates salt damage by increasing sodium, water and nutrient transport genes expression in cotton

“…1 and AtNRT2 . 2 4, 57–59 . Our previous study has shown that the non-saline root side uptakes more nutrients than the high-saline root side under non-uniform salinity 36 .…”

H+-pyrophosphatase from Salicornia europaea enhances tolerance to low phosphate under salinity in Arabidopsis

“…Furthermore, overexpression of genes (SeVP1 and SeVP2) encoding this enzyme in Arabidopsis and wheat confers tolerance to simultaneously occurring salt stress and nitrogen deficiency. 5 Here, we investigated the performance of Arabidopsis plants from the same transgenic lines under low Pi as well as low Pi plus salt conditions. For this purpose, 4-d-old seedlings were subjected to low Pi (10 mM KH 2 PO 4 , LP) and low Pi plus salt (10 mM KH 2 PO 4 with 100 mM NaCl, LPCS) stresses, with plants grown in 0.5£MS containing 1 mM KH 2 PO 4 (HP) and HPCS as the controls, respectively.…”

“…10 Previously, we have concluded that H C -PPase favors the transport of photosynthates to root, on the basis of results from carbohydrates detection in shoot and root, and the upregulation of 3 sugar transporter genes encoding AtSUC1, AtSUC2 and AtTMT1 in the transgenic Arabidopsis. 5 Furthermore, 14 C-labeling experiments in transgenic Arabidopsis overexpressing AVP1 showed enhanced photosynthesis, phloem loading, phloem transport, and delivery to sink organs. type I H C -PPases localized in the PM of sieve element-companion cell complexes (SE-CCc) is proposed to be function as PPi synthases to regulate Suc respiration for the ATP and PM proton motive force (PMF) required for Suc phloem loading.…”